The present disclosure relates to image reading devices, image forming apparatuses including an image reading device, and image processing methods.
Image forming apparatuses include an auto-document feeder to automatically convey original documents. Automatic conveyance of original documents can result in efficient reading of images of the original documents and copying of the images to sheets.
Where there is a blank document among the read original documents, in order to prevent the blank document from being copied to a sheet as it is, image forming apparatuses of some type determine whether or not a blank document is included in the original documents and performs image processing to eliminate an image of an original document determined as a blank document from to-be-copied original documents.
However, where a perforation is formed in the blank original document, a shadow is casted around the perforation in image reading, thereby disabling accurate blank document determination. In view of this, image processing devices of some type eliminate a predetermined region where a perforation is usually present from a determination region in advance to prevent mis-determination of a blank document.